The Effect of the Heat Treatment at 450°C on Distribution of Residual Stresses of Modified Cr-Mo Steel Welds

摘要

The effect of low-temperature long-term heat treatment on distribution of residual stresses on the modified chromium-molybdenum steel of the type 7 CrMoVTiB10-10 and known as T24 steel which was studied by using neutron diffraction method, is presented. The investigation of residual stress measurement by neutron diffraction was concentrated on the identification of the effect of low temperature heat treatment on stress distribution close to the circumferential weld of the steel tube. It has been recognized that the applied heat treatment did not remarkable change local properties (hardness) of the weld. Despite of this the drop of residual stresses after heat treatment compared to as welded condition was remarkable. According to the obtained results it is assumed that low temperature heat treatment can influence final behaviour of circumferential welds in service.